linux-kernel - [PATCH] drm/mxsfb: fix missing rollback on failure in mxsfb

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Message-Id: <20250313-mxsfb_probe-fix-rollback-on-error-v1-1-ad2fb79de4cb@bootlin.com>
Date: Thu, 13 Mar 2025 15:25:17 +0100
From: Luca Ceresoli <luca.ceresoli@...tlin.com>
To: Marek Vasut <marex@...x.de>, Stefan Agner <stefan@...er.ch>, 
 Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, 
 Maxime Ripard <mripard@...nel.org>, Thomas Zimmermann <tzimmermann@...e.de>, 
 David Airlie <airlied@...il.com>, Simona Vetter <simona@...ll.ch>, 
 Shawn Guo <shawnguo@...nel.org>, Sascha Hauer <s.hauer@...gutronix.de>, 
 Pengutronix Kernel Team <kernel@...gutronix.de>, 
 Fabio Estevam <festevam@...il.com>, 
 Dario Binacchi <dario.binacchi@...rulasolutions.com>, 
 Michael Trimarchi <michael@...rulasolutions.com>
Cc: Thomas Petazzoni <thomas.petazzoni@...tlin.com>, 
 dri-devel@...ts.freedesktop.org, imx@...ts.linux.dev, 
 linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org, 
 Luca Ceresoli <luca.ceresoli@...tlin.com>
Subject: [PATCH] drm/mxsfb: fix missing rollback on failure in
 mxsfb_probe()

When aperture_remove_all_conflicting_devices() fails, the current code
returns without going through the rollback actions at the end of the
function, thus the actions done by drm_dev_alloc() and mxsfb_load() are not
undone.

Fix by using a goto statament, as done for the previous and following error
conditions.

Fixes: c8e7b185d45b ("drm/mxsfb: Remove generic DRM drivers in probe function")
Signed-off-by: Luca Ceresoli <luca.ceresoli@...tlin.com>
---
The offending commit is not yet merged into master, and even less in a
released kernel, so this does not need to go through stable.
---
 drivers/gpu/drm/mxsfb/mxsfb_drv.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mxsfb/mxsfb_drv.c b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
index c183b1112bc4e9fe4f3b048a2b6e4c98d1d47cb3..b4273e678d26dbc3dee2014266d61470da4e8010 100644
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
@@ -365,9 +365,10 @@ static int mxsfb_probe(struct platform_device *pdev)
 	 * located anywhere in RAM
 	 */
 	ret = aperture_remove_all_conflicting_devices(mxsfb_driver.name);
-	if (ret)
-		return dev_err_probe(&pdev->dev, ret,
-				     "can't kick out existing framebuffers\n");
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret, "can't kick out existing framebuffers\n");
+		goto err_unload;
+	}
 
 	ret = drm_dev_register(drm, 0);
 	if (ret)

---
base-commit: f9f087d946266bc5da7c3a17bd8fd9d01969e3cf
change-id: 20250313-mxsfb_probe-fix-rollback-on-error-3074b9080f34

Best regards,
-- 
Luca Ceresoli <luca.ceresoli@...tlin.com>